MOSISO Motorcycle Sissy Bar Backrest Bag — Expandable 30L–48L Travel Duffel, Waterproof with Rain Cover

MOSISO's Motorcycle Sissy Bar Backrest Bag is an expandable, waterproof travel duffel that straps to a sissy bar or rear rack and grows from 30L to 48L for longer rides.

Designed for riders who need versatile, weather-ready luggage, this MOSISO backrest bag converts easily between a tail bag, shoulder bag and carry handbag. Built from water-resistant polyester and supplied with a full rain cover, it keeps clothing, tools and essentials protected while offering multiple mounting options and comfortable carrying features.

How much gear will this bag hold on a weekend trip?

The bag starts at a roomy 30 liters — enough for clothes, a compact helmet liner, a small toolkit and snacks — and can expand to 48 liters when you need extra room. Expansion is quick, so you can pack light or carry bulky items without needing a second bag.

• Standard volume: 30L main compartment for clothing and essentials
• Maximum expanded volume: 48L for bulky gear or extra supplies
• Front elastic cord for wet garments, towels or tools

Will it stand up to rain and road grime?

The outer fabric is water-resistant polyester and the package includes a dedicated waterproof rain cover for full protection in heavy downpours. Together these features reduce the chance of water, mud and dust penetrating your clothes and electronics during rides.

• Water-resistant polyester exterior sheds light moisture
• Included rain cover seals the bag in heavy weather
• Raised seams and zippers designed to limit water entry

How does this attach to my motorcycle and carry off-bike?

MOSISO provides two quick mounting methods: a sissy bar strap system for backrest installation and four adjustable straps to secure the bag to racks or pillion areas. Off the bike, grab the side handles or use the adjustable shoulder strap for comfortable transport.

• Sissy bar strap for fast backrest mounting
• Four adjustable straps for secure rear or rack installation
• Detachable shoulder strap (32.7"–53.9") and side carry handles

What convenience and organizational features are included?

The bag keeps frequently used items within reach thanks to its front elastic cord and large main compartment. Thoughtful touches like dual side handles, an adjustable shoulder strap and easy-access zippers make packing, carrying and mounting straightforward for any rider.

• Elastic front cord for quick storage of gloves or a towel
• Dual side handles for balanced carrying off the bike
• Large top zipper opening for fast packing and retrieval

Who is this for? Riders who want a single, adaptable luggage solution for day rides, weekend trips and commuting will find the MOSISO sissy bar backrest bag useful. It suits sportbikes, cruisers and touring bikes that accept sissy bars or rear straps, and is ideal for motorcyclists who need weather protection, expandable capacity and multiple carry options without adding hard luggage or permanent racks.